A printing system is described in the commonly assigned patent application entitled "CONTINUOUS REFILL OF SPRING BAG RESERVOIR IN AN INK-JET SWATH PRINTER/PLOTTER" now U.S. Pat. No. 5,745,137 which employs off-carriage ink reservoirs connected to on-carriage print cartridges through flexible tubing. The off-carriage reservoirs continuously replenish the supply of ink in the internal reservoirs of the on-carriage print cartridges, and maintain the back pressure in a range which results in high print quality. While this system has many advantages, there are some applications in which the relatively permanent connection of the off-carriage and on-carriage reservoirs via tubing is undesirable.
A new ink delivery system (IDS) for printer/plotters has been developed, wherein the on-carriage spring reservoir of the print cartridge is only intermittently connected to the off-carriage reservoir to "take a gulp" and is then disconnected from the off-carriage reservoir. No tubing permanently connecting the on-carriage and off-carriage elements is needed. The above-referenced applications described certain features of this new ink delivery system.